Gaya APA
GLOBAL ENVIRONMENT OUTLOOK. (1997).
NEW YORK:
UNEP.
Gaya Chicago
GLOBAL ENVIRONMENT OUTLOOK.
.
NEW YORK:
UNEP,
1997.
Text.
Gaya MLA
GLOBAL ENVIRONMENT OUTLOOK.
.
NEW YORK:
UNEP,
1997.
Text.
Gaya Turabian
GLOBAL ENVIRONMENT OUTLOOK.
NEW YORK:
UNEP,
1997.
Print.